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Questions tagged [rtc]

Real-Time Clock. Keeps track of current date/time. Some have batteries like the DS3231, and the DS3231 also has programmable alarms that can interrupt an Arduino.

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9 views

RTC DS1307 VCC not getting connected to 5V of Arduino Uno

I am using RTC DS1307 with "TINY RTC I2C modules" written on it.I had downloaded RTClib library from adafruit and using the example code. I connected GND->GND, VCC->5V, SDA->A4 and SCL->A5. However ...
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1answer
26 views

How to find the difference between two timestamps

I'm using this time library to access the properties of unix timestamps like hours / minutes / etc. What I want to do is get the current time, and an estimated arrival time, and find the difference ...
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1answer
17 views

TimeAlarms stops working when using setSyncProvider(RTC.get) DS1307

Been working on this project for some time now, like title states when I un-comment setSyncProvider(RTC.get) in the setup the program fails to get any of the Alarm.timerOnce to run. I have been stuck ...
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3answers
46 views

backup battery for FeatherWing DS3231, RTC

I am working with slightly modified example code for the Adafruit FeatherWing DS3231 RTC (real time clock) board. The DS3231 chip itself is from Maxim. Since the cell is described as a "backup battery"...
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2answers
113 views

limit length of the generated timestamp from ESP32 with DS3231 to 13

I am using ESP-WROOM-32 (Olimex ESP32-PoE) with DS3231. I have used the a patch from PR on RTClib to avoid the rollover from the DS3231. Since the DS3231 RTC provides Unix Epoch Timestamps which ...
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1answer
32 views

Apply patch to library for custom changes in Arduino IDE

I wish to obtain unix epoch timestamps in millisecond precision. I am using an ESP32 along with DS3231 RTC breakout board from adafruit. Apparently the Repository is not maintained often but I see a ...
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0answers
22 views

RTC Programming

I purchased a DS3231 AT24C32 IIC clock timer (RTC) and I have what I think are pretty simple questions. I have VCC and GND connected and jumped my NodeMCU-12E D1 and D2 pins to the RTC's SDA and SCL ...
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1answer
67 views

Hibernate Arduino for 12hrs with rtc1302 module

ok, Good morning, guys, with a data acquisition project, in this, I get data every 12 hours, even if it's only 12 hours, the arduino gets connected directly, and it's being powered by a 9v battery, ...
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1answer
101 views

exit status 1 'Time' does not name a type

#include <DS3231.h> #include <Wire.h> // i2C Conection Library // Init DS3231 DS3231 rtc; // Init a Time-data structure Time t; uint32_t targetTime = 0; uint8_t hh = 0, mm = 0, ss = 0,...
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1answer
57 views

Tiny RTC module doesn't work properly when connected to an Arduino Uno together with 16x2 LCD

I am trying to make a digital clock using a tiny RTC, 16x2 LCD, and Arduino Uno. The RTC module works fine if 16x2 LCD is not connected to the Arduino. Both RTC and LCD are I2C modules and hence are ...
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1answer
256 views

How to use RTC memory in NodeMCU to count awakes from deep sleep?

Problem: I need to retry at least 3 times (before giving up) to reconnect my NodeMCU if it doesn't get connected to Wifi, through deep sleep cycles in order to save batteries. I thought to use RTC ...
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1answer
111 views

How we can Create the folder into SD card and gives the path for file to save the data into the folder

I am trying to store files inside a series of folders, depending on month and year. I am using a RTC, and the standard SD library. I have previously gotten the program to set the file name to the ...
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1answer
127 views

Unable to save the Date and Time as the filename [closed]

I want to save the filename as current date and time
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2answers
199 views

Simulating a real time clock module with software [closed]

I am building a clock with an Arduino. Most clocks have a RTC module or some kind of RTC chip in order to get the time. I do not. How do i replace this chip with software? Is there a C/C++ library ...
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1answer
28 views

Need help with an Arduino project using a RTC and LEDs

I need some help with a project I am doing involving the DS1307 RTC. I am trying to make what is essentially a way to mins quickly check the time which involves nine LEDs slowly lighting up every 10 ...
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1answer
145 views

Is DateTime from RTClib giving garbage dates/times?

The RTC is working fine, but I'm having trouble with the DateTime class. Based on the following test, it seems like its math is wrong. #include <RTRlib.h> void loop() { auto ts = TimeSpan(0,...
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2k views

How do I set the time on my RTC DS 3231?

Well, I've bought a new RTC DS 3231, and I need to set the time on that. I tried a few libraries, but none of them seem to be working (or maybe I don't know how to use them). One library I used won't ...
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139 views

reading the time off of a RTC for portable projects with Teensy

I am trying to understand the documentation here https://www.pjrc.com/teensy/td_libs_Time.html I've spent a while testing out TimeTeensy3 and timeserial examples and I'm still very confused. Yes the ...
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0answers
402 views

Writing arrays to SD card without looping

I'm using Adafruit Feather M0 with the Adalogger FeatherWing to time-stamp and save sensor readings in an SD card. Speed is critical so I want to create two arrays, one for the readings (int) and one ...
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0answers
248 views

Building a Days Counter with Arduino Leonardo and an RTC 3231

I wanted to make a Valentine's present for my girlfriend by building a days counter since the day we got together. I've been trying to create a days counter that starts counting from a Unix timestamp ...
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0answers
125 views

Can 2 or more LED strobe Lights Flash in Sync?

I'm trying to build a strobe light that has at least 1 mode that can sync with another unit. The strobe light has 2 colors, white and red which are driven by 2 qlite drivers which are controlled by ...
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66 views

Arduino Code hang

I am working on a project to dim/brighten the LED lights between each hour. To make the program readable i have only kept the code for few hours. For example if T1 is at 255 PWM and T2 is 20 PWM, the ...
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0answers
36 views

My arrays are possibly causing the program to not enter loop?

I'm working on a project to make a digital clock with an 8x32 ws2812 LED grid, arduino uno, and a RTC module. Everything works great separately, but when I integrate it all together the code never ...
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1answer
74 views

Does a Sparkfun Redboard Arduino Uno have built-in RTC?

I have a Sparkfun Redboard (an Arduino Uno like board based on the Atmega328P and programmed with the Arduino bootloader). I have been trying to make an accurate clock without an RTC with an LCD ...
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1answer
144 views

How to Time the Arduino using RTC that I can operate the valves at 7am, 12pm, and 4 am?

The idea of this project is to open 3 valves one after the other for 5 minutes each, at a time like like 7am, 12pm, 4pm in a day. The for loop should be executed at 7am, where valve 1 is open and ...
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2answers
367 views

Using RTC DS3231 + Arduino UNO to calculate time lapsed [closed]

I am a beginner with no coding background. I am trying to figure out an alarm that tells people how long they have been sitting on their chair. The concept is very simple when the person would sit in ...
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1answer
79 views

Strange Output from DS1307 RTC

I'm using a DS1307 RTC (https://www.adafruit.com/product/3296) and an Arduino mega microcontroller trying to simply set and read the time of the RTC. However, whenever I try to output anything to the ...
2
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1answer
50 views

Advice for lower power clock type project

Arduino newbie here! I'm a programmer but my hardware knowledge is ... slim. I'd like to build a clock type wake up timer for my daughter, using an Arduino type board. Probably overkill, but it's ...
2
votes
1answer
108 views

Keep RTC time in a loop

I recently started a project with HC-SR04 sensors and RTC DS1302 clock. The idea is when a sensor detects an object, call and keep a timestamp (hh:mm:ss) all over the loop until Else If{} appears, ...
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1answer
236 views

Adafruit RTC DS3231 Crashing Arduino Uno

I am having some issues with a new DS3231 Precision RTC module. I have made connections as in the guide linked, and when used, the serial output from the Arduino is garbled, and the arduino apparently ...
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1answer
319 views

Adafruit RTC begin() not returning false

I am programming my arduino with the capability to keep time with the DS3231 from Adafruit. I do not have the module yet, but am trying to figure out the rest of the build without it. However, it ...
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1answer
802 views

DHT22 and DS18B20 together

I am trying to get DHT22 and DS18B20 to work together. The code below is the one I am using: #include <SD.h> #include "SPI.h" #include "DHT.h" #include <RTClibExtended.h> #include <...
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2answers
1k views

Arduino Uno alarm interrupt

I am trying to create a temperature-humidity monitor using Arduino and I want to power it using a battery. So, power efficiency is of interest. I am trying to put the Arduino to sleep for x-time (...
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0answers
61 views

rtc.begin() causes Nixie tubes not to fire

// // Arduinix 6 Bulb ( IN-12 ) // - Also supports Hour and Min. time set. // // This code runs a six bulb setup and displays a prototype clock setup. // NOTE: the delay is setup for IN-17 nixie ...
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1answer
344 views

PCF8583 with Arduino delay of one second?

I'm trying to interface the RTC chip : PCF8583 with Arduino Uno. I'm using exactly the circuit shown below except instead of the variable capacitor near the crystal oscillator, I've used a 22pF ...
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1answer
651 views

Setting Time to UTC with Data Logger Shield (with RTC DS1387)

I own an Adafruit Data Logger Shield https://www.adafruit.com/product/1141 I followed this tutorial https://learn.adafruit.com/adafruit-data-logger-shield/using-the-real-time-clock This part of code ...
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3answers
1k views

Calculate absolute time based on cycles and RTC

I'm developing a low power data logging device. It samples sensors at the frequency of 20Hz, and also has a real time clock for absolute time (the logged time need to be exact down to ms). I think ...
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2answers
2k views

How to code Arduino to follow schedule

I'm working on my system and I have to make arduino repeat such action or block of code if its the set time .. I'm using DS3231 module to track date and time .Example If I set the time in 6:00 AM and ...
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1answer
736 views

Problem on Arduino Interrupt and RTC

I am doing an experiment. In this experiment I want to start the RTC by presing the external Push Button which is connected with Aquino's pin 2 and take varites of action according to Time. For ...
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0answers
101 views

SD.Open causes my sketch to reboot HELP please Arduino

so you see I have this project where I have to released a specific ammount from a dispenser through sms, I attached a servo motor to the knob where it will release feeds, I also included a rtc module ...
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2answers
668 views

Tiny RTC I2C module not working

I bought a Tiny RTC I2C module and it doesn't work. When i run the TimeRTCSet from TIME library all i get is: Unable to sync with the RTC 0:00:00 0 0 1970 0:00:01 1 1 1970 0:00:02 1 1 1970 0:00:03 1 ...
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1answer
1k views

sleep and wake up arduino mega according to ds3231 interrupt

how can I make my arduino mega sleep during 6pm-7am..and wakes or stay up during 7am-6pm and doing its job like activating the solenoid valve based on my soil moisture sensor reading.this is for my ...
3
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7answers
3k views

DS1307RTC Outputting cryptic 165/165/2165 date. What are some possible fixes?

My board. I think I have it wired correctly (the lights aren't, but the board is). I've read through the first few Google results to no avail. My sample code to test the chip: // Date and time ...
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1answer
326 views

Time displays on serial monitor but not my LCD

#include <TimeLib.h> #include <Wire.h> #include <DS1307RTC.h> // a basic DS1307 library that returns time as a time_t #define PIN_SCE 7 #define PIN_RESET 6 #define PIN_DC 5 #...
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3answers
447 views

How to have some code executed at a certain time of day with a DS3231 RTC?

I recently bought a DS3231 RTC, but I cannot seem to figure out how to get it to work. I have tried all different tutorials and example programs but I keep getting 2165.25.165 165:165:165 as the ...
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0answers
655 views

sunrise alarm clock using android to set alarm time

I'm trying to create a sunrise alarm clock, controllable via Bluetooth by my phone (running android marshmallow) with an Arduino nano, real time clock module, and Bluetooth module. these will then ...
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0answers
47 views

Due to Some reasons Timer base music system has been stopped

Due to some reasons my system goes to stop. I could not find this problem so please help me with it. I am making a timer based music system. I am using two Arduino boards which communicate with each ...
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3answers
2k views

How to run a timer every 12 hours (exceeding the max size of int) without an RTC?

I'm experimenting with a Nano, and trying to trigger an action around twice a day. I'm aware that it's not super accurate, but I don't really mind, as long as it's in the ballpark. I've tried using ...
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2answers
416 views

My RTC DS1307 isn't returning any information. It seems to be stuck in the isrunning() function. Does anyone have debugging tips?

I'm using an RTC DS1307 to keep track of time for long periods. It seems to be stuck in a function. I'm using the RTClib suggested by adafruit. How can I get it unstuck and get values returned? Are ...
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0answers
274 views

How to use Servo movement with RTC with Storage error [closed]

#include <Wire.h> #include "ds3231.h" #include <Servo.h> Servo myservo; int potpin = 0; int val; int pause = 800 #define BUFF_MAX 256 ;uint8_t wake_HOUR1 = 10; uint8_t wake_MINUTE1 = 53; ...